Spin-valley dependent Klein tunneling and perfect spin- and valley-polarized transport in a magnetic WSe2 superlattice

We study spin and valley transport through a magnetic WSe2 superlattice in the presence of off-resonance circularly polarized light and gate voltage. It is demonstrated by using appropriate values of off-resonance light on the ferromagnetic region that the junction becomes gapless with a linear dispersion spectrum for each spin valley flavor. Therefore, for normal incidence, the junction is totally transparent (T = 1), a manifestation of spin-valley dependent Klein tunneling. By increasing the number of barriers, we find optically and electrically tunable spin-valley dependent transmission gaps and transmission resonances, which are also confirmed using the Bloch theorem. Consequently, a perfect spin-and valley-polarized current can be obtained, which is tunable and switchable using an exchange field, off-resonance light, and gate voltage. Our findings show the potential applications of the proposed superlattices for the spin-valley polarization and the spin-valley filtering of WSe2-based devices.